<SEC-DOCUMENT>0001104659-17-060879.txt : 20171004
<SEC-HEADER>0001104659-17-060879.hdr.sgml : 20171004
<ACCEPTANCE-DATETIME>20171004164537
ACCESSION NUMBER:		0001104659-17-060879
CONFORMED SUBMISSION TYPE:	3
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20171004
FILED AS OF DATE:		20171004
DATE AS OF CHANGE:		20171004

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			PFIZER INC
		CENTRAL INDEX KEY:			0000078003
		STANDARD INDUSTRIAL CLASSIFICATION:	PHARMACEUTICAL PREPARATIONS [2834]
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	FILING VALUES:
		FORM TYPE:		3
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-38223
		FILM NUMBER:		171122170

	BUSINESS ADDRESS:	
		STREET 1:		235 E 42ND ST
		CITY:			NEW YORK
		STATE:			NY
		ZIP:			10017
		BUSINESS PHONE:		2125732323

	MAIL ADDRESS:	
		STREET 1:		235 E 42ND ST
		CITY:			NEW YORK
		STATE:			NY
		ZIP:			10017

	FORMER NAME:	
		FORMER CONFORMED NAME:	PFIZER CHARLES & CO INC
		DATE OF NAME CHANGE:	19710908

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			RHYTHM PHARMACEUTICALS, INC.
		CENTRAL INDEX KEY:			0001649904
		STANDARD INDUSTRIAL CLASSIFICATION:	PHARMACEUTICAL PREPARATIONS [2834]
		IRS NUMBER:				462159271
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		500 BOYLSTON STREET
		STREET 2:		11TH FLOOR
		CITY:			BOSTON
		STATE:			MA
		ZIP:			02116
		BUSINESS PHONE:		857-264-4280

	MAIL ADDRESS:	
		STREET 1:		500 BOYLSTON STREET
		STREET 2:		11TH FLOOR
		CITY:			BOSTON
		STATE:			MA
		ZIP:			02116

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	RHYTHM METABOLIC, INC.
		DATE OF NAME CHANGE:	20150803
</SEC-HEADER>
<DOCUMENT>
<TYPE>3
<SEQUENCE>1
<FILENAME>a3.xml
<DESCRIPTION>3
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0206</schemaVersion>

    <documentType>3</documentType>

    <periodOfReport>2017-10-04</periodOfReport>

    <noSecuritiesOwned>0</noSecuritiesOwned>

    <issuer>
        <issuerCik>0001649904</issuerCik>
        <issuerName>RHYTHM PHARMACEUTICALS, INC.</issuerName>
        <issuerTradingSymbol>RYTM</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0000078003</rptOwnerCik>
            <rptOwnerName>PFIZER INC</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>235 EAST 42ND STREET</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>NEW YORK</rptOwnerCity>
            <rptOwnerState>NY</rptOwnerState>
            <rptOwnerZipCode>10017</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <derivativeTable>
        <derivativeHolding>
            <securityTitle>
                <value>Series A Convertible Preferred Stock</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>0</value>
            </conversionOrExercisePrice>
            <exerciseDate>
                <footnoteId id="F1"/>
            </exerciseDate>
            <expirationDate>
                <footnoteId id="F1"/>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>447514</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeHolding>
        <derivativeHolding>
            <securityTitle>
                <value>Series A-1 Junior Preferred Stock</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>0</value>
            </conversionOrExercisePrice>
            <exerciseDate>
                <footnoteId id="F1"/>
            </exerciseDate>
            <expirationDate>
                <footnoteId id="F1"/>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>940125</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeHolding>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">At any time at the Reporting Person's election or upon the closing of the Issuer's initial public offering (the &quot;IPO&quot;), each share of the Issuer's series A convertible preferred stock (the &quot;Series A Preferred&quot;) and series A-1 junior preferred stock (the &quot;Series A-1 Preferred&quot;) is convertible into shares of the Issuer's common stock on a 9.17-for-one basis without payment or consideration.  The Series A Preferred and the Series A-1 Preferred have no expiration date.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>/s/ Susan Grant, Assistant Secretary on behalf of Pfizer Inc.</signatureName>
        <signatureDate>2017-10-04</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
